The most widely used thermoelectric materials are based on inorganic compound semiconductors, many of which rely on rare or toxic elements, require high temperature processing, and/or remain mechanically inflexible. It would be desirable to develop alternative thermoelectric materials that use safer and more common elements, lend themselves to lower temperature and print processing, and can be fabricated on flexible substrates. Even more enticing are materials displaying electronic and/or thermal effects not normally associated with inorganic semiconductors that could lead to performance enhancements beyond those that have been considered limiting over the last several decades. This symposium will cover design, synthesis, processing, implementation, and performance of thermoelectric materials based on organic, polymeric, inclusion, and hybrid materials that represent departures from the classic inorganic thermoelectric phases. Theoretical principles for the design and activity of the materials are expected to further the advances in these experimental activities. For example, the ability to tune densities of states through design of molecular subunits or to tune electronic and thermal transport phenomena through interfacial effects at composite grain boundaries represent opportunities not easily available in bulk compound semiconductors. These phenomena may not be as reliant on the heavy elements or on high temperature annealing as are the compound semiconductors, and may be preparable from liquid phase precursors. The design of compatible n-type and p-type semiconductor pairs may also be more straightforward using these alternative strategies.